Added entity to the group by field list
Removing unused "reserve" import
PEP8 membership export management command
Refactoring and updating styles on membership export page
Export memberships by membership type
Reorder entity for import.
Taking Entity off of the BaseManager since it doesn't use the BaseModel.
Force a width and height on the tendenci logo.
Event speaker photos are more robust with multiple files

Previously you could not upload an event speaker photo with the same name multiple times.  Only one version of the speaker file could exist.
Merge branch 'master' into bixly-testing